Various systems have been developed as recording materials making use of energy sources such as light, heat, pressure and magnetic field alone or in combination.
In particular, a number of systems have been proposed in which separation of reactive components by means of encapsulation is used in, for example, impact paper, sensitive impact paper, fixing type sensitized paper and the like. Detailed descriptions about these systems and materials can be seen in, for example, JP-A-54-104910 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"), JP-B-64-7376 (the term "JP-B" as used herein means an "examined Japanese patent publication"), JP-B-64-7377, JP-B-64-7378, JP-A-62-132675, JP-A-62-227784, JP-A-63-186230, JP-A-64-31147, JP-A-64-59345, JP-A-64-60606 and JP-A-64-91130.
The general concept of forming an image by curing capsules making use of the sensitivity of photopolymerization systems has been applied to various fields, but not in a completely satisfactory manner since some problems were left unsolved in the prior art. For example, the prior art had shortcomings such as a desensitization problem attributable to the presence of monomers in a system in which a color former is used, insufficient sensitivity or discrimination and the like in the case of capsules containing a diazonium salt. In addition, other problems regarding preservation, color developing rate, transparency, surface coloring and the like were experienced in the prior art.
This invention offers solutions which overcome these problems encountered in the prior art.